CxxProfiler is simple sampling C/C++ profiler.
It works by attaching to a process as debugger and then periodically pausing all threads to sample call stack. After finishing analysis it shows collected samples in call graph or flat view, including relevant source code if it is available.
I wrote it few years ago, so it currently supports only executables built by Visual Studio and it runs on 64-bit Windows. Future plans include many new features - gcc/clang and cross-platform support, reducing sampling overhead, improving performance and more!
The source code is available as public domain software.